1. Field of the Invention
The present invention relates to a transmission apparatus and a transmission method, and particularly relates to a transmission apparatus and a transmission method that are suitable for transmitting a packet.
2. Description of the Related Art
Hitherto, technologies to transmit data including plural layers on a layer-to-layer basis have been developed. As an example of the above-described technologies, Japanese Patent Laid-Open No. 2004-140651 discloses the technology for distributing a code amount on time base by providing an offset at the time when encoding performed in frames for each of the layers is started. Thus, the code amount is distributed on the time base, which makes it possible to decrease a local transmission rate without changing a transmission rate determined on a per-unit-time basis, and reduce packet losses due to traffic.
According to known technologies, however, the concentration of the code amount on the time base is distributed by shifting the transmission-start time for each of the layers and/or transmitting the data corresponding to each of the layers in time areas that do not overlap with one another. That is to say, the method of transmitting the data corresponding to each of the layers is not modified according to known technologies. Therefore, it has been difficult to control the probability of the occurrence of transmission errors based on the layer importance.